Israeli swimmers won three of the opening day's six events, with world champion Mark Malyar among the victors.

Malyar, with a time of 2min 37.30sec, earned 879 points to win the men's mixed-classification 200 meters medley.

Alex Portal of France was second and Spain's Carlos Martinez Fernandez third.

Israel's Ami Omer Dadaon picked up the most points in the men's 100m freestyle, with Malyar third behind Briton Jordan Catchpole.

Dadaon was later second behind Iyad Shalabi in an Israeli one-two in the men's 150m medley.

Shalabi set a new SM1 world record, 4:57.72, in the heats.

The Netherlands' Jonne Moleman was the sole swimmer in the women's 150m medley, but produced a brilliant time of 2:39.14 to set a new world record for her classification.

British swimmers dominated the women's 100m freestyle, with Hannah Russell's 861 points leading a home one-two-three.

Toni Shaw was second and Louise Fiddes third, with Russell and Shaw both swimming faster than their respective Paralympic consideration times.

Grace Harvey, world champion Maisie Summers-Newton and Ellie Simmonds - all British SM6 athletes - were the top three in the women's 200m medley in that order, and all three dipped below the Paralympic consideration time.

Harvey led the way with a time of 3:01.01, earning 938 points, and said she was "completely over the moon with that swim".

Twenty-one countries are represented at the World Para Swimming World Series event at the Ponds Forge International Swimming Centre, which continues tomorrow.